/* Copyright 2012 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* eslint strict: ["error", "function"] */
/* eslint-disable no-extend-native */
/* globals VBArray, PDFJS */

;(function compatibilityWrapper() {
  const userAgent = navigator.userAgent

  const isAndroid = /Android/.test(userAgent)
  const isAndroidPre3 = /Android\s[0-2][^\d]/.test(userAgent)
  const isAndroidPre5 = /Android\s[0-4][^\d]/.test(userAgent)
  const isChrome = userAgent.indexOf('Chrom') >= 0
  const isChromeWithRangeBug = /Chrome\/(39|40)\./.test(userAgent)
  const isIE = userAgent.indexOf('Trident') >= 0
  const isIOS = /\b(iPad|iPhone|iPod)(?=;)/.test(userAgent)
  const isOpera = userAgent.indexOf('Opera') >= 0
  const isSafari =
    /Safari\//.test(userAgent) && !/(Chrome\/|Android\s)/.test(userAgent)

  // Initializing PDFJS global object here, it case if we need to change/disable
  // some PDF.js features, e.g. range requests
  if (typeof PDFJS === 'undefined') {
    ;(typeof window !== 'undefined' ? window : this).PDFJS = {}
  }

  // Checking if the typed arrays are supported
  // Support: iOS<6.0 (subarray), IE<10, Android<4.0
  ;(function checkTypedArrayCompatibility() {
    if (typeof Uint8Array !== 'undefined') {
      // Support: iOS<6.0
      if (typeof Uint8Array.prototype.subarray === 'undefined') {
        Uint8Array.prototype.subarray = function subarray(start, end) {
          return new Uint8Array(this.slice(start, end))
        }
        Float32Array.prototype.subarray = function subarray(start, end) {
          return new Float32Array(this.slice(start, end))
        }
      }

      // Support: Android<4.1
      if (typeof Float64Array === 'undefined') {
        window.Float64Array = Float32Array
      }
      return
    }

    function subarray(start, end) {
      return new TypedArray(this.slice(start, end))
    }

    function setArrayOffset(array, offset) {
      if (arguments.length < 2) {
        offset = 0
      }
      for (let i = 0, n = array.length; i < n; ++i, ++offset) {
        this[offset] = array[i] & 0xff
      }
    }

    function TypedArray(arg1) {
      let result, i, n
      if (typeof arg1 === 'number') {
        result = []
        for (i = 0; i < arg1; ++i) {
          result[i] = 0
        }
      } else if ('slice' in arg1) {
        result = arg1.slice(0)
      } else {
        result = []
        for (i = 0, n = arg1.length; i < n; ++i) {
          result[i] = arg1[i]
        }
      }

      result.subarray = subarray
      result.buffer = result
      result.byteLength = result.length
      result.set = setArrayOffset

      if (typeof arg1 === 'object' && arg1.buffer) {
        result.buffer = arg1.buffer
      }
      return result
    }

    window.Uint8Array = TypedArray
    window.Int8Array = TypedArray

    // we don't need support for set, byteLength for 32-bit array
    // so we can use the TypedArray as well
    window.Uint32Array = TypedArray
    window.Int32Array = TypedArray
    window.Uint16Array = TypedArray
    window.Float32Array = TypedArray
    window.Float64Array = TypedArray
  })()

  // URL = URL || webkitURL
  // Support: Safari<7, Android 4.2+
  ;(function normalizeURLObject() {
    if (!window.URL) {
      window.URL = window.webkitURL
    }
  })()

  // Object.defineProperty()?
  // Support: Android<4.0, Safari<5.1
  ;(function checkObjectDefinePropertyCompatibility() {
    if (typeof Object.defineProperty !== 'undefined') {
      let definePropertyPossible = true
      try {
        // some browsers (e.g. safari) cannot use defineProperty() on DOM objects
        // and thus the native version is not sufficient
        Object.defineProperty(new Image(), 'id', { value: 'test' })
        // ... another test for android gb browser for non-DOM objects
        const Test = function Test() {}
        Test.prototype = { get id() {} }
        Object.defineProperty(new Test(), 'id', {
          value: '',
          configurable: true,
          enumerable: true,
          writable: false
        })
      } catch (e) {
        definePropertyPossible = false
      }
      if (definePropertyPossible) {
        return
      }
    }

    Object.defineProperty = function objectDefineProperty(obj, name, def) {
      delete obj[name]
      if ('get' in def) {
        obj.__defineGetter__(name, def.get)
      }
      if ('set' in def) {
        obj.__defineSetter__(name, def.set)
      }
      if ('value' in def) {
        obj.__defineSetter__(name, function objectDefinePropertySetter(value) {
          this.__defineGetter__(name, function objectDefinePropertyGetter() {
            return value
          })
          return value
        })
        obj[name] = def.value
      }
    }
  })()

  // No XMLHttpRequest#response?
  // Support: IE<11, Android <4.0
  ;(function checkXMLHttpRequestResponseCompatibility() {
    const xhrPrototype = XMLHttpRequest.prototype
    const xhr = new XMLHttpRequest()
    if (!('overrideMimeType' in xhr)) {
      // IE10 might have response, but not overrideMimeType
      // Support: IE10
      Object.defineProperty(xhrPrototype, 'overrideMimeType', {
        value: function xmlHttpRequestOverrideMimeType(mimeType) {}
      })
    }
    if ('responseType' in xhr) {
      return
    }

    // The worker will be using XHR, so we can save time and disable worker.
    PDFJS.disableWorker = true

    Object.defineProperty(xhrPrototype, 'responseType', {
      get: function xmlHttpRequestGetResponseType() {
        return this._responseType || 'text'
      },
      set: function xmlHttpRequestSetResponseType(value) {
        if (value === 'text' || value === 'arraybuffer') {
          this._responseType = value
          if (
            value === 'arraybuffer' &&
            typeof this.overrideMimeType === 'function'
          ) {
            this.overrideMimeType('text/plain; charset=x-user-defined')
          }
        }
      }
    })

    // Support: IE9
    if (typeof VBArray !== 'undefined') {
      Object.defineProperty(xhrPrototype, 'response', {
        get: function xmlHttpRequestResponseGet() {
          if (this.responseType === 'arraybuffer') {
            return new Uint8Array(new VBArray(this.responseBody).toArray())
          }
          return this.responseText
        }
      })
      return
    }

    Object.defineProperty(xhrPrototype, 'response', {
      get: function xmlHttpRequestResponseGet() {
        if (this.responseType !== 'arraybuffer') {
          return this.responseText
        }
        const text = this.responseText
        let i
        const n = text.length
        const result = new Uint8Array(n)
        for (i = 0; i < n; ++i) {
          result[i] = text.charCodeAt(i) & 0xff
        }
        return result.buffer
      }
    })
  })()

  // window.btoa (base64 encode function) ?
  // Support: IE<10
  ;(function checkWindowBtoaCompatibility() {
    if ('btoa' in window) {
      return
    }

    const digits =
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='

    window.btoa = function windowBtoa(chars) {
      let buffer = ''
      let i, n
      for (i = 0, n = chars.length; i < n; i += 3) {
        const b1 = chars.charCodeAt(i) & 0xff
        const b2 = chars.charCodeAt(i + 1) & 0xff
        const b3 = chars.charCodeAt(i + 2) & 0xff
        const d1 = b1 >> 2
        const d2 = ((b1 & 3) << 4) | (b2 >> 4)
        const d3 = i + 1 < n ? ((b2 & 0xf) << 2) | (b3 >> 6) : 64
        const d4 = i + 2 < n ? b3 & 0x3f : 64
        buffer +=
          digits.charAt(d1) +
          digits.charAt(d2) +
          digits.charAt(d3) +
          digits.charAt(d4)
      }
      return buffer
    }
  })()

  // window.atob (base64 encode function)?
  // Support: IE<10
  ;(function checkWindowAtobCompatibility() {
    if ('atob' in window) {
      return
    }

    // https://github.com/davidchambers/Base64.js
    const digits =
      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
    window.atob = function(input) {
      input = input.replace(/=+$/, '')
      if (input.length % 4 === 1) {
        throw new Error('bad atob input')
      }
      for (
        // initialize result and counters
        var bc = 0, bs, buffer, idx = 0, output = '';
        // get next character
        (buffer = input.charAt(idx++));
        // character found in table?
        // initialize bit storage and add its ascii value
        ~buffer &&
        ((bs = bc % 4 ? bs * 64 + buffer : buffer),
        // and if not first of each 4 characters,
        // convert the first 8 bits to one ascii character
        bc++ % 4)
          ? (output += String.fromCharCode(255 & (bs >> ((-2 * bc) & 6))))
          : 0
      ) {
        // try to find character in table (0-63, not found => -1)
        buffer = digits.indexOf(buffer)
      }
      return output
    }
  })()

  // Function.prototype.bind?
  // Support: Android<4.0, iOS<6.0
  ;(function checkFunctionPrototypeBindCompatibility() {
    if (typeof Function.prototype.bind !== 'undefined') {
      return
    }

    Function.prototype.bind = function functionPrototypeBind(obj) {
      const fn = this
      const headArgs = Array.prototype.slice.call(arguments, 1)
      const bound = function functionPrototypeBindBound() {
        const args = headArgs.concat(Array.prototype.slice.call(arguments))
        return fn.apply(obj, args)
      }
      return bound
    }
  })()

  // HTMLElement dataset property
  // Support: IE<11, Safari<5.1, Android<4.0
  ;(function checkDatasetProperty() {
    const div = document.createElement('div')
    if ('dataset' in div) {
      return // dataset property exists
    }

    Object.defineProperty(HTMLElement.prototype, 'dataset', {
      get: function() {
        if (this._dataset) {
          return this._dataset
        }

        const dataset = {}
        for (let j = 0, jj = this.attributes.length; j < jj; j++) {
          const attribute = this.attributes[j]
          if (attribute.name.substring(0, 5) !== 'data-') {
            continue
          }
          const key = attribute.name
            .substring(5)
            .replace(/\-([a-z])/g, function(all, ch) {
              return ch.toUpperCase()
            })
          dataset[key] = attribute.value
        }

        Object.defineProperty(this, '_dataset', {
          value: dataset,
          writable: false,
          enumerable: false
        })
        return dataset
      },
      enumerable: true
    })
  })()

  // HTMLElement classList property
  // Support: IE<10, Android<4.0, iOS<5.0
  ;(function checkClassListProperty() {
    const div = document.createElement('div')
    if ('classList' in div) {
      return // classList property exists
    }

    function changeList(element, itemName, add, remove) {
      const s = element.className || ''
      const list = s.split(/\s+/g)
      if (list[0] === '') {
        list.shift()
      }
      const index = list.indexOf(itemName)
      if (index < 0 && add) {
        list.push(itemName)
      }
      if (index >= 0 && remove) {
        list.splice(index, 1)
      }
      element.className = list.join(' ')
      return index >= 0
    }

    const classListPrototype = {
      add: function(name) {
        changeList(this.element, name, true, false)
      },
      contains: function(name) {
        return changeList(this.element, name, false, false)
      },
      remove: function(name) {
        changeList(this.element, name, false, true)
      },
      toggle: function(name) {
        changeList(this.element, name, true, true)
      }
    }

    Object.defineProperty(HTMLElement.prototype, 'classList', {
      get: function() {
        if (this._classList) {
          return this._classList
        }

        const classList = Object.create(classListPrototype, {
          element: {
            value: this,
            writable: false,
            enumerable: true
          }
        })
        Object.defineProperty(this, '_classList', {
          value: classList,
          writable: false,
          enumerable: false
        })
        return classList
      },
      enumerable: true
    })
  })()

  // Check console compatibility
  // In older IE versions the console object is not available
  // unless console is open.
  // Support: IE<10
  ;(function checkConsoleCompatibility() {
    if (!('console' in window)) {
      window.console = {
        log: function() {},
        error: function() {},
        warn: function() {}
      }
    } else if (!('bind' in console.log)) {
      // native functions in IE9 might not have bind
      console.log = (function(fn) {
        return function(msg) {
          return fn(msg)
        }
      })(console.log)
      console.error = (function(fn) {
        return function(msg) {
          return fn(msg)
        }
      })(console.error)
      console.warn = (function(fn) {
        return function(msg) {
          return fn(msg)
        }
      })(console.warn)
    }
  })()

  // Check onclick compatibility in Opera
  // Support: Opera<15
  ;(function checkOnClickCompatibility() {
    // workaround for reported Opera bug DSK-354448:
    // onclick fires on disabled buttons with opaque content
    function ignoreIfTargetDisabled(event) {
      if (isDisabled(event.target)) {
        event.stopPropagation()
      }
    }
    function isDisabled(node) {
      return node.disabled || (node.parentNode && isDisabled(node.parentNode))
    }
    if (isOpera) {
      // use browser detection since we cannot feature-check this bug
      document.addEventListener('click', ignoreIfTargetDisabled, true)
    }
  })()

  // Checks if possible to use URL.createObjectURL()
  // Support: IE
  ;(function checkOnBlobSupport() {
    // sometimes IE loosing the data created with createObjectURL(), see #3977
    if (isIE) {
      PDFJS.disableCreateObjectURL = true
    }
  })()

  // Checks if navigator.language is supported
  ;(function checkNavigatorLanguage() {
    if ('language' in navigator) {
      return
    }
    PDFJS.locale = navigator.userLanguage || 'en-US'
  })()

  // Support: Safari 6.0+, Android<3.0, Chrome 39/40, iOS
  ;(function checkRangeRequests() {
    // Safari has issues with cached range requests see:
    // https://github.com/mozilla/pdf.js/issues/3260
    // Last tested with version 6.0.4.

    // Older versions of Android (pre 3.0) has issues with range requests, see:
    // https://github.com/mozilla/pdf.js/issues/3381.
    // Make sure that we only match webkit-based Android browsers,
    // since Firefox/Fennec works as expected.

    // Range requests are broken in Chrome 39 and 40, https://crbug.com/442318
    if (isSafari || isAndroidPre3 || isChromeWithRangeBug || isIOS) {
      PDFJS.disableRange = true
      PDFJS.disableStream = true
    }
  })()

  // Check if the browser supports manipulation of the history.
  // Support: IE<10, Android<4.2
  ;(function checkHistoryManipulation() {
    // Android 2.x has so buggy pushState support that it was removed in
    // Android 3.0 and restored as late as in Android 4.2.
    // Support: Android 2.x
    if (!history.pushState || isAndroidPre3) {
      PDFJS.disableHistory = true
    }
  })()

  // Support: IE<11, Chrome<21, Android<4.4, Safari<6
  ;(function checkSetPresenceInImageData() {
    // IE < 11 will use window.CanvasPixelArray which lacks set function.
    if (window.CanvasPixelArray) {
      if (typeof window.CanvasPixelArray.prototype.set !== 'function') {
        window.CanvasPixelArray.prototype.set = function(arr) {
          for (let i = 0, ii = this.length; i < ii; i++) {
            this[i] = arr[i]
          }
        }
      }
    } else {
      // Old Chrome and Android use an inaccessible CanvasPixelArray prototype.
      // Because we cannot feature detect it, we rely on user agent parsing.
      let polyfill = false
      let versionMatch
      if (isChrome) {
        versionMatch = userAgent.match(/Chrom(e|ium)\/([0-9]+)\./)
        // Chrome < 21 lacks the set function.
        polyfill = versionMatch && parseInt(versionMatch[2]) < 21
      } else if (isAndroid) {
        // Android < 4.4 lacks the set function.
        // Android >= 4.4 will contain Chrome in the user agent,
        // thus pass the Chrome check above and not reach this block.
        polyfill = isAndroidPre5
      } else if (isSafari) {
        versionMatch = userAgent.match(
          /Version\/([0-9]+)\.([0-9]+)\.([0-9]+) Safari\//
        )
        // Safari < 6 lacks the set function.
        polyfill = versionMatch && parseInt(versionMatch[1]) < 6
      }

      if (polyfill) {
        let contextPrototype = window.CanvasRenderingContext2D.prototype
        const createImageData = contextPrototype.createImageData
        contextPrototype.createImageData = function(w, h) {
          const imageData = createImageData.call(this, w, h)
          imageData.data.set = function(arr) {
            for (let i = 0, ii = this.length; i < ii; i++) {
              this[i] = arr[i]
            }
          }
          return imageData
        }
        // this closure will be kept referenced, so clear its vars
        contextPrototype = null
      }
    }
  })()

  // Support: IE<10, Android<4.0, iOS
  ;(function checkRequestAnimationFrame() {
    function fakeRequestAnimationFrame(callback) {
      window.setTimeout(callback, 20)
    }

    if (isIOS) {
      // requestAnimationFrame on iOS is broken, replacing with fake one.
      window.requestAnimationFrame = fakeRequestAnimationFrame
      return
    }
    if ('requestAnimationFrame' in window) {
      return
    }
    window.requestAnimationFrame =
      window.mozRequestAnimationFrame ||
      window.webkitRequestAnimationFrame ||
      fakeRequestAnimationFrame
  })()

  // Support: Android, iOS
  ;(function checkCanvasSizeLimitation() {
    if (isIOS || isAndroid) {
      // 5MP
      PDFJS.maxCanvasPixels = 5242880
    }
  })()

  // Disable fullscreen support for certain problematic configurations.
  // Support: IE11+ (when embedded).
  ;(function checkFullscreenSupport() {
    if (isIE && window.parent !== window) {
      PDFJS.disableFullscreen = true
    }
  })()

  // Provides document.currentScript support
  // Support: IE, Chrome<29.
  ;(function checkCurrentScript() {
    if ('currentScript' in document) {
      return
    }
    Object.defineProperty(document, 'currentScript', {
      get: function() {
        const scripts = document.getElementsByTagName('script')
        return scripts[scripts.length - 1]
      },
      enumerable: true,
      configurable: true
    })
  })()

  // Provides `input.type = 'type'` runtime failure protection.
  // Support: IE9,10.
  ;(function checkInputTypeNumberAssign() {
    const el = document.createElement('input')
    try {
      el.type = 'number'
    } catch (ex) {
      const inputProto = el.constructor.prototype
      const typeProperty = Object.getOwnPropertyDescriptor(inputProto, 'type')
      Object.defineProperty(inputProto, 'type', {
        get: function() {
          return typeProperty.get.call(this)
        },
        set: function(value) {
          typeProperty.set.call(this, value === 'number' ? 'text' : value)
        },
        enumerable: true,
        configurable: true
      })
    }
  })()

  // Provides correct document.readyState value for legacy browsers.
  // Support: IE9,10.
  ;(function checkDocumentReadyState() {
    if (!document.attachEvent) {
      return
    }
    const documentProto = document.constructor.prototype
    const readyStateProto = Object.getOwnPropertyDescriptor(
      documentProto,
      'readyState'
    )
    Object.defineProperty(documentProto, 'readyState', {
      get: function() {
        const value = readyStateProto.get.call(this)
        return value === 'interactive' ? 'loading' : value
      },
      set: function(value) {
        readyStateProto.set.call(this, value)
      },
      enumerable: true,
      configurable: true
    })
  })()
}.call(typeof window === 'undefined' ? this : window))
